Harry Melling was 11 in Harry Potter and the Philosopher's Stone when he played the character 'Dudley Dursley'.
That was over 23 years ago in 2001.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
Today he is 35, and has starred in 17 movies in total, 16 of those since Harry Potter and the Philosopher's Stone was released.
In Harry Potter and the Philosopher's Stone, I think Harry Melling looks: